Processes of preparing condensed polymers with polycarboxylic acids and polyamines

ABSTRACT

This invention provides processes of the preparation of polyamides, polyimides, and polyamideimides, which are easy to purify after reactions, from polycarboxylic acids and polyamines in high yield without side reactions such as a change of color to black by direct polycondensation reaction with heat, especially processes of preparing aromatic polyamides (aramids), aromatic polyimides, and aromatic polyamideimides, which are difficult to synthesize in direct polycondensation reaction. Polyamides, polymides, and polyamideimides are prepared in high yield by the polycondensation of aromatic dicarboxylic acids, aromatic tetracarboxylic acids or aromatic tricarboxylic acids and aromatic diamines, using arylboric acids such as 3,4,5-trifluorophenylboric acids as polycondensation catalysts, in a mixed solvent of pentamethylbenzene and N-methylpyrrolidinone or a mixed solvent of m-terphenyl and N-butylpyrrolidinone.

TECHNICAL FIELD

This invention relates to processes of preparing condensed polymers thatare polyamides, polyimides, or polyamidimides and more specifically, itrelates to processes of preparing condensed polymers that arepolyamides, polyimides, or polyamidimides by reacting mixtures ofpolyamines and polycarboxylic acids or the like in solvents by usingarylboric acids as polycondensation catalysts; processes of preparingcondensed polymers that are polyamides, polyimides, or polyamidimides byreacting mixtures of polyamines and polycarboxylic acids or the like byusing pentamethylbenzene as a solvent in the presence ofpolycondensation catalysts; and processes of preparing condensedpolymers that are polyamides, polyimides, or polyamidimides by reactingmixtures of polyamines and polycarboxylic acids or the like by usingm-terphenyl as a solvent in the presence of polycondensation catalysts.

BACKGROUND OF THE INVENTION

Polyamides, with amide bonds in their principal chain, are used as fibermaterials in great quantity due to their excellent frictionalresistance, elasticity, chemical resistance, and dyeability. Further,they are used not only for parts of various machines and electronics,but also for films due to their excellent mechanical,abrasion-resistant, thermo-tolerant and oilproof properties, and theirlow coefficient of friction. Polyimides, with imide bonds in theirprincipal chain, are one of most heat-resistant plastics, and are usedfor those parts of products on which high reliability is required suchas airplanes, transportation, machines, and electric or electronicmachines. Polyamideimides, with amide and imide bonds in their chain,are used for various molded materials.and insulating varnish becausethese are excellent in workabilities and abrasion resistance. Thefollowing several processes have been proposed to prepare thesepolyamides, polyimides, and polyamideimides.

In Japanese Laid-Open Patent Publication No. 49-106597, there isdisclosed a process of preparing a macromolecular aromatic polyamide bythermal polycondensation of an aromatic diamine and an aromaticdicarboxylic acid diester, or an aromatic aminocarboxylic ester withoutsolvent by using at least one compound of silicon, germanium, tin orlead as a polycondensation catalyst.

In Japanese Laid-Open Patent Publication No. 59-8728, there is discloseda process of preparing an aromatic polyamide by thermal polycondensationof an aromatic aminocarboxylic acid and/or a mixture of aromaticdicarboxylic acid and an aromatic diamine in a polar solvent in thepresence of a dehydration catalyst at a temperature of about 160° C. orover.

In Japanese Laid-Open Patent Publication No. 61-14219, there isdisclosed a stable process of preparing a polyamide and/or a polyamideacid which can be easily polycondensed, by using a sulfolane containingsubstantially no sulfolene and/or isopropylsulfolanylether as a solventin the process of preparing a polyamide and/or polyamide acid byreacting one or more polyvalent carboxylic acids and one or morediisocyanates in the presence of one or more catalysts selected fromalkali metal hydroxides, alkali metal carbonates, and alkali metalhydrogencarbonates.

In Japanese Laid-Open Patent Publication No. 8-333450, there isdisclosed a process for preparing a polyimide which is stable indimension with little residual solvent, by thermally and chemicallyimidising a polyimide precursor which is produced by reacting in a mixedsolvent of two or more solvents selected from water soluble ethercompounds, water soluble alcohol compounds, water soluble amidcompounds, water soluble ketona compounds, and water, a specificaromatic diamine compound and a tetracarboxylic acid dianhydride.

In Japanese Laid-Open Patent Publication No. 8-302015, there isdisclosed a polymide with a specific molecular weight and a specificstructural unit, which dissolves in organic solvents having a wide rangeof boiling points with high solvency, is excellent in moldingworkabilities, and has excellent thermal resistance in spite of itssoftening temperature, and is useful for varnish, modling products andthe like.

In Japanese Laid-Open Patent Publication No. 8-239470, there isdisclosed a process of preparing a water- and oil-repellent andheat-stable polyimide resin with low surface free energy and high glasstransmission temperature by reacting a specific aromatic diamine and aspecific aromatic tetracarboxylic acid dianhydride.

In Japanese Laid-Open Patent Publication No. 57-133126, there isdisclosed a process for preparing a polyamideimide by polycondensing atribasic acid anhydride and a diisocyanate compound in the presence of atertiary amine catalyst in a sulfolane solvent.

In Japanese Laid-Open Patent Publication No. 62-297329, there isdisclosed a process of preparing an aromatic polyamideimide by thermalpolycondensation of an aromatic tricarboxylic acid and/or aromatictricarboxylic acid anhydride and an aromatic diamine in the presence ofa dehydration catalyst and a solvent, wherein a compound selected fromthe group consisting of nitrobenzene, o-nitrotoluene, and benzonitrileis used as the solvent.

The present inventors, on the other hand, reported that arylboric acidswith electron-withdrawing groups such as 3,4,5-trifluorophenylboric acidand 3,5-bis(trifluoromethyl)phenylboric acid can be catalysts in amidecondensation of carboxylic acids and amines. (J. Org. Chem. 61,4196-4197, 1996)

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide processes of preparingpolyamides, polyimides, and polyamineimides, which are easy to purifyafter the reaction, and especially aromatic polyamides (aramids),aromatic polyimides, and aromatic polyamideimides, which are said to bedifficult to synthesize by direct polycondensation reactions frompolyvalent carboxylic acids and polyvalent amines with high yield andwithout side reactions such as a change in color to black.

As mentioned above, the present inventors have already reported thatarylboric acids can be a catalyst in the amide condensation ofcarboxylic acids and amines. In the case of polycondensation reactionswhere arylboric acids are used as a catalyst to prepare polyamides, itis important to select an appropriate solvent in polycondensationreaction system because the polymerization will not proceed unlesstrimers and dimers produced by the polycondensation are dissolved in thesolvent. The inventors found a process of preparing polyamides,especially aromatic polyamides (aramids), which are said to be difficultto synthesize by direct polycondensation reactions, with high yield bydirect thermal polycondensation reactions by employing combinations ofthe arylboric acids and appropriate solvents, and completed the presentinvention. The inventors also found that there are no side reactionsaccompanying a change of color to black when the direct polycondensationreactions of aromatic polyamides are performed at 200° C. or over usingpentamethylbenzene or m-terphenyl as solvents, and completed the presentinvention.

BEST MODES FOR CARRYING OUT THE INVENTION

Polyamides, polyimides, and polyamideimides are examples of thecondensed polymers in the processes of preparing condensed polymerswhere polycarboxylic acids and polyamines, polycarboxylic acids,polyamines and aminocarboxylic acids, or aminocarboxylic acids arereacted in solvents in the presence of arylboric acids aspolycondensation catalysts of the present invention, or wherepolycarboxylic acids and polyamines, polycarboxylic acids, polyaminesand amiocarboxylic acids, or aminocarboxylic acids are reacted in thepresence of polycondensation catalysts in pentamethylbenzene orm-terphenyl as solvents of the present invention. Examples diamines,semiaromatic polyamides-produced from aromatic dicarboxylic acids andaliphatic diamines, or aliphatic dicarboxylic acids and aromaticdiamines.

The polycarboxylic acids used in the present invention can be any ofthose having two or more carboxyl groups within a molecule. Dicarboxylicacids includes fumaric acid, malonic acid, adipic acid, terephthalicacid, isophthalic acid, sebacic acid, dodecanedioic acid,diphenylether-4,4′-dicarboxylic acid, pyridine-2,6-dicarboxylic acid orthe like. Tricarboxylic acids includes butane-1 2,4-tricarboxylic acid,cyclohexane-1,2,3-tricarboxylic acid, benzene-1,2,4-tricarboxylic acid,naphthalene-1,2,4-tricarboxylic acid or the like. Tetracarboxylic acidsincludes butane-1,2,3,4-tetracarboxylic acid,cyclobutane-1,2,3,4-tetracarboxylic acid,benzene-1,2,4,5-tetracarboxylic acid, 3,3′,4,4′-benzophenonetetracarboxylic acid, 3,3′,4,4′-diphenylether tetracarboxylic acid orthe like. Normally, dicarboxylic acids, tetracarboxylic acids, andtricarboxylic acids are used to prepare polyamides, polyimides, andpolyamideimides, respectively. The polycarboxylic acids can roughly beclassified into aliphatic polycarboxylic acids such as fumaric acid andcyclohexane-1,2,3-tricarboxylic acid, and aromatic polycarboxylic acidssuch as terephthalic acid.

The polyamines used in the present invention can be any of those havingtwo or more amino groups in a molecule. Diamines include diaminobutane,hexamethylenediamine, trimethyl hexamethylenediamine, m-xylilenediamine,p-phenylenediamine, m-phenylenediamine, toluylenediamine,4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylether,3,4′-diaminodiphenylether, 4,4′-diaminobiphenyl,3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminodiphenylsulfide,2,6-diaminonaphtalene, 4,4′-bis(p-aminophenoxy)diphenylsulfone,4,4′bis(m-aminophenoxy)diphenylsulfone,4,4′-bis(p-aminophenoxy)benzophenophene, 4,4′-bis(m-aminophenoxy)benzophenophene, 4,4′-bis(p-aminophenylmercapto)benzophenone,4,4′-bis(p-aminophenylmercapto)diphenylsulfone or the like. Triaminesinclude 4,4′,4″-triaminotriphenylmethane, triamterene or the like. Thepolyamines can roughly be classified into aliphatic polyamines such ashexamethylenediamine, and aromatic polyamines such as p-phenylendiamine.

The aminocarboxylic acids used in the present invention can be any ofthose having a carboxylic group and an amino group in a molecule, andcan be specifically exemplified as ω-aminoundecanoic acid,aminododecanoic acid, p-aminobenzoic acid, m-aminobenzoic acid,6-aminonaphtalene-2-carboxylic acid, 4-(p-aminophenoxy)benzoic acid,3-(p-aminophenoxy)benzoic acid, 4-(m-aminophenoxy)benzoic acid,3-(m-aminophenoxy)benzoic acid or the like.

The arylboric acids used in the present invention can be any arylboricacid as long as then can act as a catalyst in polycondensingpolycarboxylic acids and polyamines, polycarboxylic acids, polyaminesand aminocarboxylic acids, or aminocarboxylic acids in the presence ofsolvents. However, it is preferable to use phenylboric acids withelectron withdrawing groups at least at one of the 3,4, and 5 positions,which can be specifically exemplified as 3,4,5-trifluorophenylboricacid, 3-nitrophenylboric acid, 3,5-bis(trifluoromethyl)phenylboric acid,3,5-bis(trifluoromethyl)phenylboric acid, and4-trifluoromethylphenylboric acid. Among these,3,4,5-trifluorophenylboric acid is the most desirable one in view ofyield. Electron withdrawing groups can be exemplified as —CF₃, —F, —NO₂,—CN, —⁺NH₃, —CHO, —COCH₃, —CO₂C₂H₅, —CO₂H, —SO₂CH₃, —SO₃H and the like.The arylboric acids used as polycondensation catalysts in the presentinvention are particularly advantageous in commercial working becausethey are stable, and can be easily retrieved.

As a polycondensation catalyst in the process of preparing condensedpolymers by reacting polycarboxylic acids and polyamines, polycarboxylicacids, polyamines and aminocarboxylic acids, or aminocarboxylic aminesin the presence of polycondensation catalysts by usingpentamethylbenzene as a solvent in the present invention, it can be anyof those capable of catalyzing polycondensation reaction of thosestarting materials in the presence of solvents containingpentamethylbenzene. As a polycondensation catalyst in the process ofpreparing condensed polymers in reacting polycarboxylic acids andpolyamines, polycarboxylic acids, polyamines and aminocarboxylic acids,or aminocarboxylic acids in the presence of polycondensation catalystsby using m-terphenyl as a solvent in the present invention, it can beany of those usable as a catalyst in polycondensing those startingmaterials in the presence of solvents containing m-terphenyl. Apart fromarylboric acids such as 3,4,5-trifluorophenylboric acid mentioned above,various boron compounds, phosphorus compounds, and heteropolyacids canbe used as well.

Phosphorus compounds can be exemplified as phosphites such as trimethylphosphite, triethyl phosphite, tributyl phosphite, triphenyl phosphite,tricresyl phosphite, tricyclohexyl phosphite, diethyl phosphite,diphenyl phosphite, and o-methyl-s,s′-diphenyl dithiophosphite;phosphates such as tributyl phosphate, triphenyl phosphate, ethylphenylphosphate, and ethylenephenyl phosphate; phosphoric acids such asphosphoric acid, pyrophosphoric acid, methaphosphoric acid,tetrapolyphosphoric acid, trimethaphosphoric acid, andethylmetaphosphoric acid; phosphonic acids such as phenylphosphonicacid; phosphines such as triphenyl phosphine and trioctyl phosphine;phosphine oxides such as triphenylphosphine oxide, and1-phenylphospholine-3-oxide; and other compounds such as phosphoruspentoxide, ammonium dihydrogenphosphate,p-diethyltrimethylsilylphosphate, N,N′,N″-hexamethylphosphorus triamide,tetrabutylpyrophosphite, phenylphonus acid,tetrakis-(2,4-ditertiarybutylphenyl)-4,4′-biphenylene diphosphonite,distearyl pentaerythritol diphosphite.

As for a solvent in the process of preparing condensed polymers byreacting polycarboxylic acids and polyamines, polycarboxylic acids,polyamines and aminocarboxylic acids, or aminocarboxylic acids, usingarylboric acids as polycondensation catalysts in the present inventionin the presence of solvents, it can be exemplified aspentamethylbenzene, m-terphenyl, xylene, cresol, toluene, benzene,ethylbenzene, 1,3,5-triisopropylbenzene, o-dichlorobenzene,1,2,4-trichlorobenzene, cyclohexane, cyclopentane, phenol, naphthalene,1,2,3,4-tetrahydronaphthalene (tetralin), acetophenone, benzophenone,diphenylsulfone, N-methylpyrrolidinone (N-methylpyrrolidone),N-butylpyrrolidinone (N-butylpyrrolidone), N-ethylpyrrolidone,N-methyl-2-pyrrolidone, 1,3-dimethyl-2-pyrrolidone,N,N-dimethylformamide, dimethylacetoamide, hexamethylphosphoramide,dimethylsulfoxide, nitromethane, acetonitrile, pyridine,1,3-dimethyl-2-imidazolidinone, Υ-butylolactone.

Among these solvents, in polycondenseing aromatic polycarboxylic acidsand aromatic polyamines, it is desirable to use pentamethylbenzene orm-terphenyl, or more preferably, a mixed solvent of pentamethylbenzeneand N-methylpyrrolidinone having a weight ratio of 70:30-90:10 or amixed solvent of m-terphenyl and N-butylpyrrolidinone having a weightratio of 3:1-10:1.

As a solvent used in the polycondensation of aliphatic dicarboxylicacids such as adipic acid and aliphatic diamines such ashexamethylendiamine, it is preferable to use a solvent containingo-xylene. Further, it is preferable to add m-cresol to o-xylene toeffectively dissolve aliphatic amides such as nylon 6,6 prepared by thepolycondensation and to proceed the reaction more sufficiently. Thedesirable amount of the m-cresol added is 10-30 wt %, that is, it isdesirable to use a 70:30-90:10 mixed solvent of o-xylene and m-cresol,especially a mixed solvent having a volume ratio of 4:1. In the casewhere the amount of the m-cresol added is too much, the catalyticactivity may be hampered. Further, it was also found that a desirableresult was obtained when pentamethylbenzene or m-terphenyl was usedinstead of o-xylene. As is the case of o-xylene, when usingpentamethylbenzene or m-terphenyl, it is desirable to use a mixedsolvent of pentamethylbenzene and m-cresol having a weight ratio of70:30-90:10, or a mixed solvent of m-terphenyl and m-cresol having aweight ration of 70:30-90:10.

As a solvent containing pentamethylbenzene or m-terphenyl in the presentinvention, the solvents containing pentamethylbenzene or m-terphenyl areused in the process of preparing polyconsdensation products by reactingpolycarboxylic acids and polyamines, polycarboxylic acids, polyaminesand aminocarboxylic acids, or aminocarboxylic acids in the presence ofpolycondensation catalysts using pentamethylbenzene or m-terphenyl as asolvent. In the case where 1,3,5-triisopropylbenzene,1,2,4-trichlorobenzene, tetralin, cresol or the like is used assolvents, the color of the reaction system turns to black. However, itwill not turn to black even when it is heated up to 200° C. by usingpentamethylbenzene, and up to 300° C. by using m-terphenyl, and thechange of color will be prevented. The change of color may be attributedto some side reactions due to the fact that it also occurs in thereaction conducted under a deoxidized atmosphere.

In the case where aromatic polyamides or the like are prepared as acondensed polymer by polycondensation, it is preferable to addN-methylpyrrolidinone (NMP) to pentamethylbenzene to efficientlydissolve the product obtained by the reaction and to sufficientlyproceed the polycondensation reaction. The amount of theN-methylpyrrolidinone added is preferably 10-30 wt %, that is, it ispreferable to use a mixed solvent of pentamethylbenzene andN-methylpyrrolidinone having a weight ratio of 70:30-90:10, and morepreferably, a 4:1 mixed solvent of them. In the case where the amount ofthe N-methylpyrrolidinone added is too much, the catalytic activitymaybe hampered. Further, in the case where aromatic polyamides areproduced as condensed polymers by polycondensation, it is preferable toadd N-butylpyrrolidinone (NBP) to m-terphenyl to effectively dissolvethe product obtained by the reaction and to sufficiently proceed thepolycondensation reaction. The desirable amount of theN-butylpyrrolidinone added is 9-25 wt %, that is, it is desirable to usea mixed solvent of m-terphenyl and N-butylpyrrolidinone having a weightratio 3:1-10:1, and more desirably, a 10:1 mixed solvent of them. In thecase where the amount of the N-methylpyrrolidinone added is too much,the catalytic activity may be hampered. Further, when aromaticdicaroxylic acids and aromatic diamines as starting materials are largein molecular weights, the reaction becomes effective by adding moresolvent without changing the ratio of a mixed solvent.

On the other hand, in the case where aliphatic polyamides etc. areproduced by polycondensation, it is desirable to add m-cresol topentamethylbenzene or m-terphenyl to dissolve the product obtained bythe reaction effectively and to proceed the reaction more sufficiently.The amount of the m-cresol added is preferably 10-30 wt %, that is, itis preferable to use a mixed solvent of pentamethylbenzene orm-terphenyl and m-cresol having a volume ratio of 70:30-90:10, and morepreferably, a 4:1 mixed solvent of them. In the case where the amount ofthe m-cresol added is too much, the catalytic activity may be hampered.Further, when the aromatic polycaroxylic acids and aromatic polyaminesas starting materials are large in molecular weights, the reactionbecomes effective by adding more solvent without changing the ratio of amixed solvent.

It is preferable to conduct the polycondensation in a process ofpreparing condensed products in the present invention under a deoxidizedatmosphere or an argon atmosphere. The deoxidized atmosphere can beachieved by conducting the reaction in the presence of an inert gas. Inan argon atmosphere, it is preferable to conduct the polycondensationreaction under argon flow, and with this argon atmosphere in a reaction,the effects of dehydration and a deoxidized atmosphere can be achievedat the same time.

Further, in the case where aromatic polycarboxylic acids and aromaticpolyamines are polycondensed in pentamethylbenzene as solvents, thereaction should preferably be conducted at 160-240° C., more preferablyat 200° C., while stirring and in m-terphenyl as solvents, it shouldpreferably be conducted at 200-300° C., more preferably at 300° C.,while stirring. In the case where aliphatic polycarboxylic acids andaliphatic polyamines are polycondensed, the reaction should preferablybe conducted at 140-200° C., more preferably at 150° C., while stirring.The polyamides, polyimides, and poliamideimides prepared in theprocesses of condensation can be purified by the previously well knownprocesses of purification. As mentioned above, side reactions do notoccur in the processes of preparation in the present invention, andtherefore the products produced by the present processes can be purifiedmore easily than those produced by the previously well known processes.

The invention will be more clearly understood with reference to thefollowing examples. The scope of this invention, however, is notrestricted in any way by the following examples: Example 1

Synthesis of Aramid

Aramid was synthesized by the polycondensation reaction indicated inreaction formula (chemical formula 1). Isophthalic acid (4 mmol, 0.665g), p-phenylenediamine (4 mmol, 0.433 g), pentamethylbenzene (the amountobtained by subtracting the NMP amount from the amount of the totalsolvent 5 g in Table 1), N-methylpyrrolidinone (NMP) (the weight %against the total amount of solvent 5 g in Table 1),3,4,5-trifluorophenylboric acid (the amount represented in mol % inTable 1) was put in a Schlenk, and were stirred at 200° C. or 170° C.(temperature of oil bath represented in Table 1) for specifictime(reaction times set forth in Table 1). During the stirring, argonwas continuously poured to remove the water slowly (about 20 ml/min).After the reaction, the mixture was cooled to room temperature, andcrude products of powdery aramids were obtained by adding acetone 50 mland filtering. Further, after the crude products had been heated andrefluxed in methanol (50 ml) for one hour, they were cooled to roomtemperature and refined by filtering. The isolation yields of aramidsare shown in Table 1. In the case where the amount of the catalyst was 5mol %, and the concentration of the NMP in a solvent was 20 wt % inTable 1, the catalysts were retrieved after the polycondensationreaction. After the reaction products were filtered, the filtrate wasconcentrated, and the catalyst was purified by using silica gelchromatography, showing that a retrieval rate was 71%.

TABLE 1 Amount of Concentration Reaction Reaction Solvent of NMPTemperature Time Yield (mol %) in Solvents (° C.) (h) (%) 0 20 wt % 1704 12 10 20 wt % 170 4 55 0 20 wt % 200 4 47 5  0 200 4 66 5  5 wt % 2004 86 5 10 wt % 200 4 92 5 20 wt % 200 4 96 5 30 wt % 200 4 87 5 40 wt %200 4 30 1 20 wt % 200 24 >99

Example 2 Synthesis of Keylar

Terephthalic acid (4 mmol, 0.665 g), p-phenylenediamine (4 mmol, 0.433g), pentamethylbenzene (4 g), N-methylpyrrolidinone (NMP) (1 g), and3,4,5-trifluorophenylboric acid (0.04 mmol, 7.1 mg) were put in aSchlenk, and stirred at 200° C. (temperature of oil bath) for one day.During the stirring, argon was poured continuously to remove the waterslowly. After the reaction, it was cooled to room temperature andpowdery crude keylar was obtained by adding 50 ml acetone and filtering.Further, after the crude product had been heated and refluxed for onehour in methanol (50 ml), it was cooled to room temperature, andpurified by filtering. The isolation yield of keylar was 99% or more(968 mg, light yellow powder).

Example 3 Synthesis of Nomex

Next, various aromatic dicarboxyic acids (4 mmol), various aromaticdiamines (4 mmol), pentamethylbenzene (4 g), N-methylpyrrolidinone (NMP)(1 g), and 3,4,5-trifluorophenylboric acid (0.04 mmol) were poured intoa Schlenk and stirred at 200° C. (temperature of oil bath) for one day.The other conditions were the same as in Example 2. Whenm-phenylenediamine and isophthalic acid were polycondensed as inchemical formula 2, the isolation yield of nomex was 99% or more. As tothe isolation yield of keylar, the same result was obtained for a caseof chemical formula 3, where p-phenylenediamine and terephthalic acidwere polycondensed. The isolation yield of nomex was 97% for a case ofchemical formula 4, where diaminodiphenylether and isophthatic acid werepolycondensed. The isolation yield of tellurone was 42% for a case ofchemical formula 5, where p-aminobenzoic acid was polycondensed.

Example 4 Synthesis of Aramid

Aramid was synthesized following the polycondensation reaction indicatedin chemical formula 6. Isophthatic acid (1 mmol, 0.166 g),p-phenylenediamine (1 mmol, 0.108 g), m-terphenyl (the amount obtainedby subtracting NBP from the amount of the total solvent 4 g in Table 2),N-butylpyrrolidinone(NBP) (the weight % against the total amount ofsolvent 4 g in Table 2) and 3,4,5-trifluorophenylboric acid (the amountrepresented in mol % in Table 2) were poured in a Schlenk, and werestirred at 300° C. (temperature of oil bath) for certain time (reactiontimes in Table 2). During the stirring, argon was poured continuously toremove the water slowly (about 20 ml/min). After the reaction, it wascooled to room temperature, 30 ml acetone was added and the mixture wasfiltered to obtain the powdery crude aramid. Further, the crude productwas heated and refluxed in methanol (15 ml) for one hour, and cooled toroom temperature, and purified by filtering. The treatment with methanolwas repeated three times. The isolation yield of aramid is indicated inTable 2. In the case of the amount of the catalyst was 10 mol % and theNBP concentration in the solvent was 9 wt % in Table 2, the catalyst wasretrieved after the polycondensation reaction. Following the filtrationof the reaction product, the filtrate was concentrated, and the catalystwas purified by silica gel chromatography, showing that the retrievalrate was 71%. η_(inh) in “a” in Table 2 indicates the result when it ismeasured in concentrated sulfuric acid of 0.0667 g/dl at 25° C., and “b”indicates the result of the measurement of the relative averagemolecular weights measured by GPC (gel permeation chromatography) bydissolving 2 wt % purified aramid in NBP containing 0.01 M LiCl and 0.05M H₃PO₄ using polystyrene as a standard reference material.

TABLE 2 Concen- Amount tration Reaction of of NBP Tem- Solvent inperature Reaction Yield η_(inh) ^(a) Mn^(b)/ Mw^(b)/ (mol %) solvents (°C.) Time (%) (dl/g) 10⁴ 10⁴ 1 9 wt % 300 2 days >99 0.90 — — 1 25 wt % 300 2 days >99 — 1.15 2.83 10  9 wt % 300 2 h  84 — — — 0 9 wt % 300 2 h 34 — — —

Example 5 Synthesis of Keylar

Terephthalic acid (1 mmol, 0.166 g), p-phenylenediamine (1 mmol, 0.108g), m-terphenyl (3.33 g), N-butylpyrrolidinone (NBP) (0.67g), and3,4,5-trifluorophenylboric acid (0.1 mmol, 17.8 mg) were poured into aSchlenk, and stirred at 300° C. (temperature of oil bath) for two days.During the period, argon was poured continuously to remove the waterslowly (about 20 ml/min). After the reaction, it was cooled to roomtemperature, and powdery crude product of keylar was obtained by adding30 ml acetone and filtering. Further, the crude product was heated andrefluxed in methanol (15 ml), cooled to room temperature, and filteredfor purification. The treatment with methanol was repeated three times.In the case of chemical formula 7, where p-phenylenediamine andterephthalic acid were polycondensed, the isolation yield of keylar was98% (954 mg, light yellow powder). It had η_(inh)=1.19 dl/g (measured inconcentrated sulfuric acid solution of 0.067 g/dl at 25° C.).

Example 6 Synthesis of Aramid

Terephthalic acid (1 mmol), di(4-aminophenyl) ether (1 mmol),m-terphenyl (3.64 g), N-butylpyrrolidinone (NBP) (0.36 g), and3,4,5-trifluorophenylboric acid (0.1 mmol) were poured into a Schlenk,and stirred at 300° C. (temperature of oil bath) for two days. The otherconditions were the same as in Example 5. In the case of chemicalformula 8, where the condensation polymerization of di(4-aminophenyl)ether and terephthalic acid was conducted, the isolation yield of thearamid was 98% (white powder). It had η_(inh)=0.90 dl/g (measured inconcentrated sulfuric acid of 0.067 g/dl at 25° C.).

Example 7 Synthesis of Aramid

Next, various carboxylic acids (1 mmol), various aromatic amines (1mmol), m-terphenyl (3 g), N-butylpyrrolidinone (NBP) (1 g), and3,4,5-trifluorophenylboric acid (0.1 mmol) were poured into a Schlenk,and stirred at 300° C. (temperature of oil bath) for two days. The otherconditions were the same as in Example 5. The isolation yield was 78% inthe case of polycondensation of amino acids as shown in chemical formula9. In the case of polycondensation of 1,4-diaminobenzene and1,3-adamantanedicarboxylic acid as shown in chemical formula 10, theisolation yield of aramid was >99%, and η_(inh) was 0.30 dl/g (measuredin concentrated sulfuric acid solution of 0.067 g/dl at 25° C.). In thecase of polycondensation of di(4-aminophenyl) ether and1,3-adamantanedicarboxylic acid as shown in chemical formula 11, theisolation yield of aramid was 91%, and η_(inh) was 0.60 dl/g (measuredin concentrated sulfuric acid of 0.067 g/dl at 25° C.).

Example 8 Synthesis of Aramid

Isophthalic acid (1 mmol), di(4-aminophenyl) ether (1 mmol), m-terphenyl(3.63 g), N-butylpyrrolidinone (NBP) (0.37 g), and3,4,5-trifluorophenylboric acid (0.01 mmol) were poured into a Schlenk,and stirred at 300° C. (temperature of oil bath) for two days. The otherconditions were the same as in Example 5. In the case ofpolycondensation of di(4-aminophenyl) ether and isophthalic acidindicated in chemical formula 12, the isolation yield of aramidwas >99%, and η_(inh) was 0.60 dl/g (measured in concentrated sulfuricacid solution of 0.067 g/dl at 25° C.).

Example 9 Synthesis of Polyimide

Amines (1 mmol), carboxylic acids (1 mmol), m-terphenyl (3 g),N-butylpyrrolidinone (NBP) (1 g), and 3,4,5-trifluorophenylboric acid(0.01 mmol), as shown in chemical formula 13, were poured into aSchlenk, and stirred at 300° C. (temperature of oil bath) for two days.The other conditions are the same as in Example 5. The isolation yieldof polyimide was 97%.

Example 10 Synthesis of Polyimide

Next, various carboxylic acids (1 mmol), various aromatic amines (1mmol), m-terphenyl (3.63 g), N-butylpyrrolidinone (NBP) (0.67g), and3,4,5-trifluorophenylboric acid (0.01 mmol) were poured into a Schlenk,stirred at 200° C. (temperature of oil bath) for one day, and thenstirred at 250° C. (temperature of oil bath) for one day, and finallystirred at 300° C. (temperature of oil bath) for one day. The otherconditions were the same as in Example 5. In the case ofpolycondensation of amines and carboxylic acids indicated in chemicalformula 14, the isolation yield of polyimide was 93%. And in the case ofpolycondensation of amines and carboxylic acids indicated in chemicalformula 15, the isolation yield of polyimide was 96%.

Example 11 Synthesis of Nylon 9,T

Terephthalic acid (1 mmol), 1,9-diaminononane (1 mmol), m-terphenyl(3.63 g), N-butylpyrrolidinone (NBP) (0.37 g), and3,4,5-trifluorophenylboric acid (0.01 mmol) were poured into a Schlenk,and stirred at 200° C. (temperature of oil bath) for one day, and thenstirred at 250° C. (temperature of oil bath) for one day, and finallystirred at 300° C. (temperature of oil bath) for one day. The otherconditions were the same as in Example 5. In the case ofpolycondensation of 1,9-diaminononane and terephthalic acid indicated inchemical formula 16, the isolation yield of nylon 9,T was 94%. Themolecular weight of the product measured as a 2.5 mg/ml solution ofhexafluoroisopropanol (HFIP) containing 0.01 M sodium trifluoroacetateby GPC with poly(methylmethacrylate) as a standard material, wasMn=103,000 and Mw=2,292,000.

Example 12 Synthesis of Nylon 6.6

Nylon 6,6 was synthesized by the condensation polymerization reactionindicated in the reaction formula (chemical formula 17). Adipic acid(2.5 mmol), hexamethylenediamine (2.5 mmol), 3,4,5-trifluorophenylboricacid (the amount indicated in Table 2 represented in mol %), solvent (4ml of the solvent indicated in Table 2, weight ratio of toluene toxylene was 3:1, and that of xylene to NMP was 4:1) were poured into aflask, and were heated and refluxed (the reaction temperature and timeindicated in Table 2). During the reaction, a Soxhlet's extractor wasconnected to the top of the flask, and molecular sieve 4A was poured,and the water was removed. After the reaction, it was cooled to roomtemperature, and acetone (30 ml) was added to filtrate. The powderynylon was purified by washing with water and acetone. The result isshown in Table 3.

TABLE 3 Amount of Reaction Solvent Temperature Time Yield (mol %)Solvent (° C.) (h) (%) Mn Mw Mw/Mn Mz/Mn 10 Toluene 150 20 82 1010  26802.65 2.19 10 Toluene- 150 20 83 Cresol  0 Toluene- 150 20  0 Cresol 10Xylene 150 20 89 2680  8330 3.11 2.12 10 Xylene- 150 20 85 4690 224004.78 2.02 Cresol  1 Cresol 180 24 86  0 Cresol 180 24 60  1 Xylene- 15024 74 NMP

Example 13 Synthesis of Polyamide

Dicarboxylic acid derivatives of adamantane and diamine derivatives andthe like were poured into a flask together with3,4,5-trifluorophenylboric acid (1 mol %) as polycondensation catalistand mesitylene as solvent, and then heated and refluxed for twentyhours. The isolation yield of polyamide indicated in chemical formula 18was 96%, and the isolation yield of polyamide indicated.in chemicalformula 19 was 99%. It was confirmed that semiaromatic nylon 6T wasprepared from terephthalic acid and hexamethylenediamine, that polyimidewas prepared from benzene-1,2,4,5-tetracarboxylic acid andhexamethylendiamine, and that polyamideimide was prepared from benzene-1,2,4-tricarboxylic acid and hexamethylendiamine with high yield foreach process by the polycondensation reactions in the presence of3,4,5-trifluorophenylboronic acid as polycondensation catalyst andhexamethylbenzene as solvent.

INDUSTRIAL APPLICABILITY

This invention makes it possible to produce polyamides, polyimides andpolyamideimides, which are easy to purify after reaction frompolycarboxylic acids and polyamines by direct thermal polycondensationwith high yield and without side reactions such as a change of color toblack, and especially to produce aromatic polyamides (aramids), aromaticpolyimides, and aromatic polyamideimides, which are said to be difficultto prepare by direct thermal polycondensation.

What is claimed is:
 1. A process of preparation of a condensed polymerby reacting a polycarboxylic acid and a polyamine, a polycarboxylicacid, a polyamine and an aminocarboxylic acid, or an aminocarboxylicacid in the presence of a polycondensation catalyst and a solvent,wherein an arylboric cid is used as the polycondensation catalyst. 2.The process as claimed in claim 1, wherein the condensed polymer ispolyamyde, polyimide, or polyamideimide.
 3. The process as claimed inclaim 1, wherein the phenylboric acid has an electron-withdrawing groupat least at one of the 3,4, and 5 positions.
 4. The process as claimedin claim 3, wherein the phenylboric acid having an electron-withdrawinggroup at least at one of the 3,4, and 5 positions is one or morearylboric acids selected from 3,4,5-trifluorophenylboric acid,3-nitrophenylboronic acid, 3,5-bis(trifluoromethyl)phenylboric acid,3,5-bis(trifluoromethyl) phenylboric acid or4-trifluoromethylphenylboric acid.
 5. The process as claimed in claim 1,wherein the condensed polymer is polyamide, and the polycarboxylic acidand the polyamine, the polycarboxylic acid, the polyamine and theaminocarboxylic acid, or the aminocarboxylic acid comprises anycombination of an aromatic dicarboxylic acid and an aromatic diaamine,an aromatic dicarboxylic acid and an aliphatic diamine, an aliphaticdicarboxylic acid and an aromatic diamine or an aliphatic dicarboxylicacid and an aliphatic diamine.
 6. The process as claimed in claim 5,wherein an aromatic dicarboxylic acid and an aromatic diamine are usedas the combination of an aromatic dicarboxylic acid and an aromaticdiamine, an aromatic dicarboxylic acid and an aliphatic diamine, analiphatic dicarboxylic acid and an aromatic diamine, or an aliphaticdicarboxylic acid and an aliphatic diamine.
 7. The process as claimed inclaim 6, wherein terephthalic acid and p-phenylendiamine are used as thearomatic dicarboxylic acid and the aromatic diamine.
 8. The process asclaimed in claim 1, wherein an aromatic tetracarboxylic acid and analiphatic diamine are used for a combination of the polycarboxylic acidand the polyamine, the polycarboxylic acid, the polyamine and theaminocarboxylic acid, or the aminocarboxylic acid, and the condensedpolymer is polyimide.
 9. The process as claimed in claim 1, wherein anaromatic tricarboxylic acid and an aromatic diamine are used for acombination of the polycarboxylic acid and the polyamine, thepolycarboxylic acid, the polyamine and the aminocarboxylic acid, or theaminocarboxylic acid, and the condensed polymer is polyamideimide. 10.The process as claimed in claim 1, wherein the solvent used containspentamethylbenzene.
 11. The process as claimed in claim 10, wherein amixed solvent of pentamethylbenzene and N-methylpyrrolidinone is used asthe solvent containing pentamethylbenzene.
 12. The process as claimed inclaim 11, wherein a mixed solvent of pentamethylbenzene andN-methylpyrrolidinone having a weight ratio of 70:30-90:10 is used asthe mixed solvent of pentamethylbenzene and N-methylpyrrolidinone. 13.The process as claimed in claim 1, wherein a solvent containingm-terphenyl is used as the solvent.
 14. The process as claimed in claim13, wherein a mixed solvent of m-terphenyl and N-butylpyrrolidinone isused as the solvent containing m-terphenyl.
 15. The process as claimedin claim 14, wherein a mixed solvent of m-terphenyl andN-butylpyrrolidinone having a weight ratio of 3:1-10:1 is used as themixed solvent of m-terphenyl and N-butylpyrrolidinone.
 16. The processas claimed in claim 1, wherein the reaction is performed under adeoxidized atmosphere.
 17. The process as claimed in claim 1, whereinthe reaction is performed under an argon atmosphere.
 18. The process asclaimed in claim 5, wherein an aliphatic dicarboxylic acid and analiphatic diamine are used for the combinations of an aromaticdicarboxylic acid and an aromatic diamine, an aromatic dicarboxylic acidand analiphatic diamine, an aliphatic dicarboxylic acid and an aromaticdiamine, or an aliphatic dicarboxylic acid and an aliphatic diamine. 19.The process as claimed in claim 18, wherein adipic acid andhexamethylenediamine are used as the aliphatic dicarboxylic acid and thealiphatic diamine.
 20. The process as claimed in claim 18, wherein asolvent containing o-xylene is used as the solvent.
 21. The process asclaimed in claim 20, wherein a mixed solvent of o-xylene and m-cresol isused as the solvent containing o-xylene.
 22. The process as claimed inclaim 18, wherein a mixed solvent of o-xylene to m-cresol having avolume ratio of 70:30-90:10 is used as the mixed solvent of o-xylene andm-cresol.
 23. The process as claimed in claim 18, wherein a mixedsolvent of pentamethylbenzene and m-cresol is used as the solvent. 24.The process as claimed in claim 18, wherein the reaction is performed at140-200° C.
 25. The process as claimed in claim 18, wherein a mixedsolvent of m-terphenyl and m-cresol is used as the solvent.
 26. Theprocess as claimed in claim 25, wherein the reaction is performed at140-300° C.
 27. A process of preparation of a condensed polymer byreacting a polycarboxylic acid and a polyamine, a polycarboxylic acid, apolyamine and an aminocarboxylic acid, or an aminocarboxylic acid, inthe presence of a polycondensation catalyst and a solvent, wherein asolvent containing pentamethylbenzene is used as the polycondensationsolvent.
 28. The process as claimed in claim 27, wherein the condensedpolymer is polyamide, polyimide, or polyamideimide.
 29. The process asclaimed in claim 27, wherein polyamide is prepared as the condensedpolymer, and the polycarboxylic acid and the polyamine, thepolycarboxylic acid, the polyamine and the aminocarboxylic acid, or theaminocarboxylic acid comprise any combination of an aromaticdicarboxylic acid and an aromatic diamine, an aromatic dicarboxylic acidand an aliphatic diamine, an aliphatic dicarboxylic acid and an aromaticdiamine, or an aliphatic dicarboxylic acid and an aliphatic diamine. 30.The process as claimed in claim 29, wherein an aromatic dicarboxylicacid and an aromatic diamine are used as the combinations of an aromaticdicarbocylic acid and an aromatic diamine, an aromatic dicarboxylic acidand an aliphatic diamine, an aliphatic dicarboxylic acid and an aromaticdiamine, or an aliphatic dicarboxylic acid and an aliphatic diamine. 31.The process as claimed in claim 30, wherein terephthalic acid andp-phenylenediamine are used as the aromaic dicarboxylic acid and thearomatic diamine.
 32. The process as claimed in claim 29, wherein analiphatic dicarboxylic acid and an aliphatic diamine are used as thecombinations of an aromatic dicarboxylic acid and an aromatic diamine,an aromatic dicarboxylic acid and an aliphatic diamine, an aliphaticdicarboxylic acid and an aromatic diamine, or an aliphatic dicarboxylicacid and an aliphatic diamine.
 33. The process as claimed in claim 32,wherein adipic acid and hexamethylenediamine are used as the aliphaticdicarboxylic acid and the aliphatic diamine.
 34. The process as claimedin claim 27, wherein an aromatic tetracarboxylic acid and an aliphaticdiamine are used as the polycarboxylic acid and the polyamine, thepolycarboxylic acid and the polyamine and the aminocarboxylic acid, orthe aminocarboxylic acid, and the condensed polymer is polyimide. 35.The process as claimed in claim 27, wherein an aromatic tricarboxylicacid and an aromatic diamine are used as the polycarboxylic acid and thepolyamine, the polycarboxylic acid, the polyamine and theaminocarboxylic acid, or the aminocarboxylic acid and the condensedpolymer is polyamideimide.
 36. The process as claimed in claim 27,wherein a mixed solvent of pentamethylbenzene and N-methylpyrrolidinoneis used as the solvent containing pentamethylbenzene.
 37. The process asclaimed in claim 36, wherein a mixed solvent of pentamethylbenzene andN-methylpyrrolidinone having a weight ratio of 70:30-90:10 is used asthe mixed solvent of pentamethylbenzene and N-methylpyrrolidinone. 38.The process as claimed in claim 27, wherein a mixed solvent ofpentamethylbenzene and m-cresol is used as the solvent containingpentamethylbenzene.
 39. The process as claimed in claim 27, wherein anarylboric acid is used as the polycondensation catalyst.
 40. The processas claimed in claim 39, wherein phenylboric acid with anelectron-withdrawing group at least at one of the 3,4, and 5 positionsis used as the arylboric acid.
 41. The process as claimed in claim 40,wherein one or more arylboric acids selected from3,4,5-trifluorophenylboric acid, 3-nitrophenylboric acid,3,5-bis(trifluoromethyl)phenylboric acid, or4-trifluoromethylphenylboric acid are used as the phenylboric acid withan electron-withdrawing group at least at one of the 3,4, and 5positions.
 42. The process as claimed in claim 27, wherein the reactionis performed under a deoxidized atmosphere.
 43. The process as claimedin claim 27, wherein the reaction is performed under an argonatmosphere.
 44. A polyamide compound prepared by polycondensation of anaromatic dicarboxylic acid and an aromatic diamine in the presence of anarylboric acid as a polycondensation catalyst and a mixed solvent ofpentamethylbenzene and N-methylpyrrolidinone.
 45. A polyimide compoundprepared by polycondensation of an aromatic tetracarboxylic acid and anaromatic diamine in the presence of an arylboric acid as apolycondensation catalyst and a mixed solvent of pentamethylbenzene andN-methylpyrrolidinone.
 46. A polyamideimide compound prepared bypolycondensation of an aromatic tricarboxylic acid and an aromaticdiamine in the presence of an arylboric acid as a polycondensationcatalyst and a mixed solvent of pentamethylbenzene andN-methylpyrrolidinone.
 47. A process of preparation of a condensedpolymer by reacting a polycarboxylic acid and a polyamine, apolycarboxylic acid, and a polyamine and an aminocarboxylic acid, or anaminocarboxylic acid in the presence of a polycondensation catalyst anda solvent containing m-terphenyl is used as the solvent.
 48. The processas claimed in claim 47, wherein polyamide, polyimide, or polyamidimideis prepared as the polycondensed polymers.
 49. The process as claimed inclaim 47, wherein the condensed polymer is polyamide, and thepolycarboxylic acid and the polyamine, the polycarboxylic acid, and thepolyamine and the aminocarboxylic acid, or the aminocarboxylic acidcomprises any combination of an aromatic dicarboxylic acid and anaromatic diamine, an aromatic dicarboxylic acid and an aliphaticdiamine, an aliphatic dicarboxylic acid and an aromatic diamine or analiphatic dicarboxylic acid and an aliphatic diamine.
 50. The process asclaimed in claim 49, wherein an aromatic dicarboxylic acid and anaromatic diamine are used as the combination of an aromatic dicarboxylicacid and an aromatic diamine, an aromatic dicarboxylic acid and analiphatic diamine, an aliphatic dicarboxylic acid and an aromaticdiamine, or an aliphatic dicarboxylic acid and an aliphatic diamine. 51.The process as claimed in claim 50, wherein terephthalic acid andp-phenylenediamine are used as the aromatic dicarboxylic acid and thearomatic diamine.
 52. The process as claimed in claim 49, wherein analiphatic dicarboxylic acid and an aliphatic diamine are used as thecombinations of an aromatic dicarboxylic acid and an aromatic diamine,an aromatic dicarboxylic acid and an aliphatic diamine, an aliphaticdicarboxylic acid and an aromatic diamine, or an aliphatic dicarboxylicacid and an aliphatic diamine.
 53. The process as claimed in claim 52,wherein adipic acid and hexamethylenediamine are used as the aliphaticdicarboxylic acid and the aliphatic diamine.
 54. The process as claimedin claim 47, wherein the condensed polymer is polyimide, and thepolycarboxylic acid and the polyamine, the polycarboxylic acid and thepolyamine and the aminocarboxylic acid or the aminocarboxylic acidcomprises an aromatic tetracarboxylic acid and an aliphatic diamine. 55.The process as claimed in claim 47, wherein the condensed polymer ispolyamideimide, and the polycarboxylic acid and the polyamine, thepolycarboxylic acid, the polyamine and the aminocarboxylic acid or theaminocarboxylic acid comprises an aromatic tricarboxylic acid and anaromatic diamine.
 56. The process as claimed in claim 47, wherein amixed solvent of m-terphenyl and N-butylpyrrolidinone is used as thesolvent containing m-terphenyl.
 57. The process as claimed in claim 56,wherein a mixed solvent of m-terphenyl and N-butylpyrrolidinone having aweight ratio of 3:1-10:1 is used as the mixed solvent of m-terphenyl andN-butylpyrrolidinone.
 58. The process as claimed in claim 47, wherein amixed solvent of m-terphenyl and m-cresol is used as the solventcontaining m-terphenyl.
 59. The process as claimed in claim 47, whereinan arylboric acid is used as the polycondensation catalyst.
 60. Theprocess as claimed in claim 59, wherein phenylboric acid with anelectron-withdrawing group at least at one of the 3,4, and 5 positionsis used as the arylboric acid.
 61. The process as claimed in claim 60,wherein one or more arylboric acids selectedfrom3,4,5-trifluorophenylboric acid, 3-nitrophenylboric acid,3,5-bis(trifluoromethyl)phenylboric acid, 4-trifluorophenylboric acidare used as the phenylboric acid with an electron-withdrawing group atleast at one of the 3,4, and 5 positions.
 62. The process as claimed inclaim 47, wherein the reaction is performed under a deoxidizedatmosphere.
 63. The process as claimed in claim 47, wherein the reactionis performed under an argon atmosphere.
 64. A polyamide compoundprepared by polycondensation of an aromatic dicarboxylic acid and anaromatic diamine in the presence of an arylboric acid as apolycondensation catalyst and a mixed solvent of m-terphenyl andN-butylpyrrolidinone.
 65. A polyimide compound prepared bypolycondensation of an aromatic tetracarboxylic acid and an aromaticdiamine in the presence of an arylboric acid as a polycondensationcatalyst and a mixed solvent of m-terphenyl and N-butylpyrrolidinone.66. A polyamideimide compound prepared by polycondensation of anaromatic tricarboxylic acid and an aromatic diamine in the presence ofan arylboric acid as a polycondensation catalyst and a mixed solvent ofm-terphenyl and N-butylpyrrolidinone.